Treatment of steel rails.



mas? AVALE P. H. DANIELS. TREATMENT OF STEEL RAILS.

APPLICATION FILED NOV. 21, 1907.

941, 1 34. Patented Nov. 23, 1909.

QBHEETS-SHEET 1.

F. H. DANIELS.

TREATMENT OF STEEL RAILS APPLICATION FILED NOV. 21, 1907. Patented Nov.23, 1909 2 SHEETS-SHEET 2.

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TREATMENT OF STEEL RAILS.

illg. Specification of Application filed November 21, 1907.

To all whom it may concern:

Be it known that I, FRED H. DANIELS, a citizen of the United States,residing at lVorcester, in the county of lVorcester and State ofD'Iassachusetts, have invented a certain new and useful Treatment ofSteel Rails, of which the following is a specification.

The great weight and high speed of modern railway trains subject therails to very hard usage, and it is therefore important that the railspossess the greatest possible durability and resistance to shocks.

In a copending application filed of even date herewith, Ser. No.403,139, I have de scribed and claimed broadly a mode of treatment bywhich improved results in respect of durability and lessened liabilityof fracture are obtained. The method referred to consists, brieflystated, in suddenly cool ing or chilling the heated rail, preferably ata temperature of about 1400 to 1600 F., thereby imparting a finecrystalline structure to the metal, but producing internal strains whichmust be relieved before the rail is in condition for eflicient use; thenreheating the rail, say to a temperature of about 900 F. which is belowa chill red heat, and allowing it to cool gradually, thus removing theinternal strains and leaving the rail hard and tough. My presentinvention involves a similar procedure, but adds thereto an importantstep which materially improves the wearand shock-re sisting qualities ofthe rail. The step referred to consists in flattening and elongating thecrystals of. the metal, more especially at the head and base of therail, by passing the cooled rail one or more times through suitablerolls or dies.

In the annexed drawings I have illustrated, somewhat diagrammatically,convenient apparatus for practicing the invention.

In the drawings, Figure 1 is a plan view of a complete apparatus for thepurpose, in which the sudden chilling of the heated rail is effected bya bath of oil, and the reheating by a bath of molten lead. Fig. 2 is asection on line II-II of Fig. 1, showing the oil and lead baths, withtheir asso ciated mechanism. Fig. 3 is a similar section showing a leadbath for effecting the sudden cooling or chilling and a hot room orchamber for reheating the cooled rail. Fig. at is a diagrammaticelevation of a set Patented Nov. 23, 1909. Serial No. 403,141.

Letters Patent.

of rolls for rolling the rail after its slow cooling.

In carrying out my invention, the treatment begins with the rails at agood red heat, say from 1600 to 1800 F. By preference they are finishedat that heat in the finishing rolls, indicated by l in the drawings,from which they are delivered by con veying tables 2 to the hot saws 3,where they are cut into suitable lengths for use. Leaving the hot saws,the rails are engaged by teeth or projections at on endless chains orother suitable conveyers 5 and carried thereby along guides 6, 7, intoand through a bath of oil contained in a vessel 8. The rails are thuscooled rapidly, and the metal is thereby caused to assume a finecrystalline structure. At the same time internal strains are produced,which are removed in the following manner.

From the oil bath the rails are moved along the guides 6 and 8 into andthrough a bath of molten lead, contained in a vessel 9 and maintained atthe proper temperature by furnaces 10, 11. The rails are reheated,preferably to a temperature below a dull red heat, in the lead bath, andare clelivered therefrom to the conveying rollers 12 leading to a hotbed 13. In being drawn slowly over the hotbed the rails cool gradually,with the result that the internal strains, produced by the previoussudden chilling, are eradicated. Instead of chilling the heated rails inoil and reheating them in molten lead, they maybe chilled in molten leadand reheated in a suitable hot room, as described and claimed in mycopending application filed of even date herewith, Ser. No. 403,140. Anapparatus for carrying out this treatment is illustrated in Fig. 3, andoperates as follows. Receiving the heated rails from the hot saws 3 theconveyer chains 5 carry them along the guides 6 into and through a bathof molten lead contained in a receptacle 14 provided with furnaces 15,16, for maintaining the metal in the molten state. The sudden chillingof the heated rails by the molten lead imparts a fine crystallinestructure to the steel, but, as before stated, also produces internalstrains. The latter are eradicated as follows: From the lead bath theconveyers carry the rails along the guides 6, 6 into a suitable hotroom, heated by furnaces 15, 16, to a temperature suflicient to reheatthe rails, say to a temperature below a dull red heat. From the hotroom, as from the reheating lead bath of Fig. 2, the reheated rails aretaken to the hot bed and there cooled gradually. The cooled rails arenow rolled or drawn to flatten and elongate the crystals of the metal.For this purpose an arrangement of rolls like those illustrated in Fig.4 may be employed. In this figure the roll 17 operates on the top andsides of the head, rolls 20 and 21 on the web, and roll 22 on the edgesand bottom of the base. Passed one or more times through these rolls,the structure of the metal of the rail is materially modified, moreparticularly in the exterior parts of the rail, the crystals beingflattened and elongated and the whole toughened. After the cold-rolling,the rails are straightened, if necessary, and then drilled, by suitableapparatus not shown, whereupon they are ready for use.

From the foregoing it will be seen that the method of treatment issimple, and can be practiced with apparatus of simple character. At thesame time the treatment is thoroughly effective, rendering the railsmaterially more durable and more resistant to fracture.

lVhat I claim is:

1. The herein described method of treating steel rails to increase theresistance thereof to wear and shocks, which consists in cooling theheated rail rapidly, and thereby imparting to the metal a linecrystalline structure; reheating the rail and then cooling the samegradually, to eliminate internal strain; and cold-rolling the rail toelongate and flatten the crystals of the metal.

2. The herein described method of treating steel rails to increase theresistance thereof to wear and shocks, which consists in cooling theheated rail rapidly by subjecting the same to a liquid cooling medium,to impart a fine crystalline structure to the metal; reheating the railand then cooling the same gradually to eliminate internal strains; andcold-rolling the rail to elongate and flatten the crystals of the metal.

3. The herein described method of treating steel rails to increase theresistance thereof to wear and shocks, which consists in rapidly coolingthe rail from red heat and thereby imparting a fine crystallinestructure to the metal; reheating the rail to a temperature ofapproximately 900 F. and

then cooling the same gradually to eliminate internal strains; andcold-rolling the rail to elongate and flatten the crystals of the metal.

at. The herein described method of treating steel rails to increase theresistance thereof to wear and shocks, which consists in subjecting thered hot rail to a liquid cooling medium, to cool the rail rapidly andimpart a fine crystalline structure to the metal; reheating the rail toa temperature of approximately 900 F. and then gradually cooling therail on a hot bed, to eliminate internal strains; and passing the cooledrail through rolls to elongate and flatten the crystals of the metal.

5. The herein described method of treating steel rails to increase theresistance thereof to wear and shocks, which consists in rapidly coolingthe heated rail and thereby impart ing a fine crystalline structure tothe metal; reheating the rail and then cooling the same gradually, toeliminate internal strains; and flattening and elongating the crystalsof the metal exterior parts of the rail.

FRED H. DANIELS. lVitnesses:

M. A. BACON, G. LAMPsoN.

